The uniquely shaped lab at Beauty Mark, with observation windows above, also was used as the operating room in Season 2's A Stitch in Crime (1973).
Actor David Toma, who plays a police officer, was a real-life policeman who had a one-season TV series named after him: "Toma (1973)." However, in the series, Toma was played by Tony Musante.
In A Stitch in Crime (1973), a tired, early-morning Columbo also carries around his makeshift breakfast: an uncracked, hard-boiled egg that he carries around, looking for a place to open it. This was meant to be a part of Columbo's makeup, along with the raincoat and his cigar. There are several episodes (especiallly in the 90s reboot) where Columbo wanders around trying to find a place to toss the cracked eggshells.
Columbo tells Viveca she is like Lydia E. Pinkham, who, in the mid-1800s, marketed "Lydia E. Pinkham's Vegetable Tonic," a cure-all for women's troubles, from menstrual cramps, to menopausal hot flashes, to general hysteria, which was deemed a uniquely, female disorder. By the early 1900s, her tonic was in most household medicine cabinets.